A suchlike positioning mechanism is described in application WO 2014/076262, for example. Said earlier document is incorporated by reference. Said mechanism comprises a positioning lever 101 exhibiting a flat lateral edge so arranged as to cooperate with a flat 97 provided on the staff of the pinions 96, 98, 100 and is utilized to pivot and reposition the pinions 96, 98, 100 perfectly when the displacement cycle of the information carrier is completed.
However, said mechanism does not permit the fine adjustment of the positioning lever, which is frequently a requirement in the field of watchmaking. In particular, a suchlike mechanism does not make it possible to guarantee the initial positioning or the correct repositioning of a toothing intended to cooperate with another toothing for periods. As a result, the risks of engagement faults when starting or when restarting the toothed wheel following a temporary stop are considerable.